The blowing of a container is achieved in a mold the wall of which defines a cavity in which the parison is introduced. During the blowing process, the parison molds the shape of the wall under the high gaseous pressure within the parison, after it has been heated in order to allow for its plastic deformation.
It is known to equip the mold with a thermal regulation system. Depending upon the targeted uses of the containers, either the mold is cooled in order to maintain its temperature at a level lower than the temperature of vitreous transition (e.g. in the manufacturing of containers suitable for receiving still water, wherein the mold is maintained within the range of 20-60° C.), or the mold is heated to temperatures greater than the temperature of vitreous transition, in order for the material to have a crystallinity great enough, such that the container is made resistant to deformation during a hot filling (such containers are called “heat resistant” or “HR”).
Thermal regulation is achieved through circulation of a cooling or heating fluid (e.g. water or oil) in at least one channel formed within the sidewall of the mold. Depending upon the extent of the thermal regulation, either of a part of the mold only or of the whole mold, the channel may extend on the whole height of the mold, or be localized in a specific area (such as in the vicinity of the neck or the bottom of the container).
In general, the channel opens on an outer face of the mold and has an inlet port connected to a fluid supply line, and an outlet port connected to a fluid discharge line. Circulation of the fluid is achieved through a pump located outside the mold. During the setting process, including the replacement of the mold, the inlet and discharge lines need to be disconnected from the mold to be replaced, and connected back to the new mold.
U.S. Pat. No. 6,444,159 and U.S. Pat. No. 6,447,281 to Sidel, Inc. give an overview of this technology, which, in the inventors' opinion, is satisfactory but needs to be enhanced, for the connection of the supply and discharge lines to the mold is somewhat unpractical.